Sheriff Matt English of Hood River County said Jason Endicott, 25, was among a group of five people who hiked to the top of the falls late Sunday afternoon.

Four of the five jumped into water, which a television meteorologist estimated to be about 45 degrees. The three who survived the jump have not been identified; one of them was treated in an ambulance for hypothermia and released.

"By the time I got there, there were about seven people, and everybody was just sitting on him with their body warmth trying to keep him warm because he was so wet and cold," witness Claudette Rushing said of the man with hypothermia. "And I had one of those emergency foil blankets that we put on him."

Endicott never surfaced, and a search for him was halted for the night late Sunday. Endicott's cause of death wasn't immediately known.

People regularly jump off the falls when the temperatures rise. The water looks inviting after a hike, but jumping is risky, English said, with the threat of currents and thick sediment making the water shallower that it appears.

A sign at the trailhead warns that cliff jumping into the shallow pool below the waterfall is illegal and may result in a $300 fine.

"There have been problems here in the past," Sheriff's Sgt. Pete Hughes said. "It's a dangerous thing to do."

Divers resumed the search for Endicott's body Monday.

English said it could be a complicated and dangerous recovery. The rescuers must hike two and a half miles up a trail with their gear and then navigate the rough water at the base of the falls.

"It's really close to the falls," English said. "They're going to be dealing with a lot of undertow."

Sunday's rescue operation was the second of the weekend at Punch Bowl Falls.

On Friday, a search and rescue team helped a man who suffered neck and back injuries after jumping off the falls. The man, whose identity was not available, was taken to a hospital.